1. Technical Field
The present invention relates a transmission for a hybrid vehicle, in more detail, a transmission for a hybrid vehicle having a plurality of power split modes and a plurality of fixed-gear ratio shift stages.
2. Related Art
A hybrid vehicle equipped with a hybrid transmission formed by assembly of an engine, one or more motor generators, and one or more planetary gear sets can travel in an electric vehicle mode in which the power from the motor generator(s) is used to get the vehicle started or operate the vehicle at a low velocity and in a power split mode in which the power from the engine and the power from the motor generator(s) are used with a transmission (e.g., Electrically Variable Transmission (EVT)) when the velocity of the vehicle increases. In some cases, a fixed-stage gear ratio can be used to improve power performance of the vehicle. Advantages of such a hybrid vehicle include high fuel efficiency and low emission.
Researches have been made to provide a new transmission that can contribute improve fuel efficiency with higher operation performance. There is, however, still need for an improved transmission.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.